We do not know what the pixels of the style transferred result should be, so we instead optimize this output using a cycle loss between \(T\)  and features extracted from \(O\)  [1]}:
\(\mathcal {L}_{cycle}=\frac{16}{H_CW_C}\sum _{i=0}^{\frac{H_CW_C}{16}}D \Big (T_i, \hspace{5.69046pt}\Phi (O)_i \Big )\) 
